1. Field of the Invention
The present invention relates to a mobile communication device and an antenna structure therein, and more particularly, to a mobile communication device with a built-in antenna having a shielding metal wall and multi-frequency operating bands.
2. Description of the Prior Art
With the rapid progress of wireless technology, the long term evolution (LTE) mobile technology has been promoted. Antennas of mobile communication devices are required to have lower operating frequencies and wider bandwidths, that is, their operating bands must cover from about 704 MHz to 960 MHz and from about 1710 MHz to 2690 MHz so as to satisfy the three-band LTE700/2300/2500 operation and the five-band WWAN operation. Mobile communication devices are required to be light and small, such that small size and multi-band operations become essential design considerations. Furthermore, under multi-functional demands, the integration of an internal antenna and other electronic elements on the system circuit board of the mobile communication device is increasing. Hence, how to design a multi-frequency antenna with a shielding metal wall to effectively perform the integration of the antenna and other electronic elements on the system circuit board of the mobile communication device and satisfying the wideband operation has become an important topic in this field.
In the prior art, such as TW patent No. 1327786 with the invention entitled “AN EMC INTERNAL MEANDERED LOOP ANTENNA FOR MULTIBAND OPERATION”, a multiband meandered loop antenna having a meandered loop radiator for multiband operation integrated with an antenna ground plane acted as a shielding metal wall has been disclosed. Such multiband meandered loop antenna has an operating band covering the five-band WWAN operation, however, its operating band cannot cover the eight-band LTE/WWAN operation.
Hence, how to provide a mobile communication device with the wide operating band at least covering from about 704 MHz to 960 MHz and from about 1710 MHz to 2690 MHz to satisfy the eight-band LTE/WWAN operation and perform the integration of an internal antenna and other electronic elements on the system circuit board of the device has become an important topic in this field.